Henri-Joseph Redouté, the mathematician Gaspard Monge (a founding member of the École polytechnique), the chemist Claude Louis Berthollet, Vivant Denon, the mathematician Jean-Joseph Fourier (who did some of the empirical work upon which his "analytical theory of heat" was founded in Egypt), the physicist Étienne Malus, the naturalist Étienne Geoffroy Saint-Hilaire, the botanist Alire Raffeneau-Delile, and the engineer Nicolas-Jacques Conté of the Conservatoire national des arts et métiers. Their original aim was to help the army, notably by opening a Suez Canal, mapping out roads and building mills to supply food. They founded the Institut d'Égypte with the aim of propagating Enlightenment values in Egypt through interdisciplinary work, improving its agricultural and architectural techniques for example. A scientific review was created under the title Décade égyptienne and in the course of the expedition the scholars also observed and drew the flora and fauna in Egypt and became interested in the country's resources. The Egyptian Institute saw the construction of laboratories, libraries, and a printing press. The group worked prodigiously, and some of their discoveries were not finally cataloged until the 1820s. A young engineering officer, Pierre-François-Xavier Bouchard, discovered the Rosetta Stone in July 1799. Many of the antiquities collected by the French in Egypt were seized by the British Navy and ended up in the British Museum – only about 50 of the 5,000 Egyptian objects in the Louvre were collected during the 1799–1801 Egyptian expedition. Even so, the scholars' research in Egypt gave rise to the 4-volume Mémoires sur l'Égypte (published 1798–1801). A subsequent and more comprehensive text was Description de l'Égypte, published on Napoleon's orders between 1809 and 1821. Publications such as these of Napoleon's discoveries in Egypt gave rise to fascination with Ancient Egyptian culture and the birth of Egyptology in Europe. The scientists also tested methods in hot air ballooning while in Egypt. Several months after the Cairo Revolt in 1798, inventor Nicolas-Jacques Conté and mathematician Gaspard Monge built a hot air balloon from paper, coloured with the tricolour red, white and blue of the French Republic. They launched the balloon above Azbakiyya Square above a crowd of spectators, but the balloon soon fell to earth, causing panic among the spectators. The French had also planned to demonstrate hot air balloon flight during their celebrations of the anniversary of the founding of the French Republic in 1798, but the scientists had lost their equipment at the